Pellets vs. Whole leaf hops

In the year I have been brewing, I only have used whole leaf hops once (Cascade) for bittering a beer. I have a 7.5 gal kettle and usually try to collect 6.5-6.75 gal of wort for boiling so I was concerned about whole leaf hops taking up too much room and causing a boilover. I also was concerned that in making a hoppy beer like an IPA they would absorb too much liquid.

My question is: Are there certain hop varieties that are better used as whole leaf as opposed to pellet, or does it not matter? Does using strictly whole leaf hops have advantages?

Some places only use whole hops (Sierra Nevada) and many homebrewers like whole hops because the trub is easier to separate in the kettle. High alpha-acid hops are better for bittering as you don't need to use as many, and have less chance of developing a vegetative taste from all the plant material. And as for them sucking up your wort, that's just a recipe change. If you want to you can also squeeze all that hoppy wort out of the whole hops.

Now for the bad news, you get less utilization (around 10%) with whole hops as opposed to pellets. Whole hops also don't store as well as pellets.

I prefer whole hops to pellets most of the time, especially for hoppy beers as I don't as good of a hop aroma/flavor with pellets IMO. But, I will use pellets for bittering additions or beers without a great american hop presence. I'll never use pellets for flavor/aroma/dry additions for an american ale though.

I really don't notice a difference, to be honest! Not even with dryhopping.

I've known other brewers who say that they get better aroma with dryhopping with whole hops, though.

In my experience it hasn't mattered much at all. I went through the "hop crisis" of 2007, where I took whatever I could find and wasn't disappointed with the differences between leaf and pellets.

i have to smile whenever i hear the "hops crisis of 2007" i'm a water lawyer and the younger generations of our field have a running joke whenever someone mentions the "great flood of 1993" (which wasn't all that great) as if they'd survived the dust bowl of the 1930s. but i'm sure the hops crisis was quite a challenge and an opportunity at the same time

i find pellet hops easier to work with during the boil and more effecient, but whole hops easier for dry hopping with less mess.